How do I cut text through an object?
You need to create a solid 3D mesh out of the Text to get the Boolean Modifier working. 

Select the text mesh and drag it up (z axis) a little. Use a solidify modifier and adjust its thickness until the text mesh goes through the Scoreboard mesh (you don't need to apply it). 

Select the Scoreboard mesh, add a Boolean Modifier, select "Difference" as operation and "Text" as the object to use for the modifier. 

Here's the .blend file with unapplied modifiers: